My Dad's '57 4 door only had one key (my older brother bought it new). I'm pretty sure that's the way the came. Our '57 has 2 one for ignition and one for the trunk and doors, but that's not original. I have also heard that at that time GM only made a few sets of keys and every 6 or 7 one was a master key, I do know that the key to fit Dad's car, fit my buddies '57 coupe, and our football coaches '61 impala, would unlock and start both of them. Go figure.:sign0020: